Conventionally, when a surgical instrument, such as an endoscope, is inserted into the body of a patient, surgical operation navigation (surgical operation assistance information display) that assists an operator is performed, in which the accurate position of the tip end of the surgical instrument is displayed on an image by CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) photographed before the surgical operation. However, this method only displays the position of the tip end of the instrument, such as a surgical instrument and pointer, but it does not display to which part of the image before operation by CT or MRI, the region the image of which is being picked up by the endoscope corresponds.
If it is possible to confirm to which part of the image by CT etc. before operation, the region (field to be operated on displayed on the monitor of the endoscope) the image of which is being picked up by the endoscope corresponds, it is possible for an operator to confirm the position to be operated on in the direct vision by the endoscope held in his/her left hand, and to continuously carry out the operational processing by exchanging arbitrary surgical instruments with his/her right hand while recognizing which region of the image by CT etc. before operation is observed. With the arrangement, the surgical instrument does not require any special marker and it is possible to use any instrument without limitations.
As a technique that can solve the above-described problem, there is one disclosed in Patent Document 1, which displays the region observed by an endoscope on an image (by CT/MRI) before operation.
Patent document 1: Japanese Unexamined Patent Publication No. 2001-204738